Compressed-air brake.



J. DE LIPKOWSKI.

GOMPRESSED AIR BRAKE.

PPLIUATION FILED 11110.13, 1911.

Patented Jan; 13, 1914.`

BWSA mgl Egg

NVENTOR `LDB LIPKOWSKI.

GOMPRESSED AIR BRAKE.

APPLIGATION FILED 11110.13, 1911.

1,084,574. I Patented Jan. 13, 1914.

2 SHEETS-SHEET 2.

UNITED sTATEs PATENT oEEioE.

JOSEPH DE LIPKOWSKI, F `PARIS, FRANCE.

coMPREssED-ATR BRAKE.

SpeeicatonA of Letters Patent. Application fried December 13,1911.

Serial No. 665,552.

o To all who/nett may concern:

Be it known that I, JOSEPH DE Lirnowsnr, of 9a Boulevard Flandrm, Paris, France,

engineer, have invented certain newandk useful Improvements yinV Compressed Air Brakes, of whichetherfollowing is a full, clear, andeXact description.l

The present invention relates to improve ments in compressedair ,brakes which are controllable kat application and at release, and in which there exists a direct vand con'- stant relation between kthe air pressure in the train-pipe or the like and the air-pres sure in the brake cylinders (upon the pistons), both at application and at releaseand independently of the piston-stroke, that is to say, independentlyofthe wear of the blocks. l

l These improvements relate bothto the distributer and to the accelerator. of this type of brake, and consist in the following :(a) The distributer of this brake is constructed in such a manner that the lubricating oil carried along by the compressed air, instead of being deposited in the different parts of f the distributer and hindering its operation,

is stopped upon entering the distributer and collected in a special sump whence it can be removed from time to time. (b) One of the diaphragms mounted upon the distributerpiston is replaced by a cup-leather, which is more easily itted and can be replaced without having to dismount the whole mechanism; (c) The two remaining diap-hragms are fitted so as to be easily replaced also Y without having to dismount the whole apparatus; (d) The distributer piston-rod may Y be extended to carry a second cup leather;

the action exerted by the rair upon this latter counterbalances that exerted upon the first and renders the action of the brake more sensitive.

The complete brake for one vehicle comprises a brake cylinder of the ordinary type with a piston, an air vessel termed the brake reservoir, a special air distributer at present called the triple valve,`and a small reservoir called the distributer reservoir. In the case 4of a quick acting brake, there is added an accelerator.

The essential part of the brake is the air distributer which regulates the action of the brake. The remainder vor" the apparatus consist-sof the cocks, the couplings andthe sys-V tem of pipes which are. sufficiently simple to need no further description.'V

yslide valve.

.The object of Ythe distributer is to maintain a strict and constant relation between the fall of pressure made in the train pipe by the driver and the air pressure admitted to the brake cylinder, and this independently of the size of the cylinder which varies with different brakes according to the stroke of the piston which in turn depends upon the amount of wear of the brake shoes. To obtain this result it is necessary to render the action of the distributer absolutely independent o the air pressure in the brake reservoir and to replace this pressure whichV continually varies according to the stroke of the piston of the brake cylinder, by a con-l stant pressure derived from air stored in a small separate reservoir which is termed they distributer reservoir. i

The following description has reference to the accompanying drawings in which Figure l is a longitudinal section of the apparatus. Fig. 2 is a section at right angles to Fig. l with the internal portions ,of the apparatusremoved. Fig. 3 is a transverse Patented Jan.13,1914. Y

section on the line 3-3of Fig. l. Fig. 4 is.-

another transverse section on the line t-,t `of Fig. 2. Fig. 5 shows the detail ofthe respond respectively-to the running position, preparatory and release, neutral or kcut out position and braking position. v

The workingr part of the distributer consists of a slide valve A operated by al piston rod VB Xed to two diaphragms B and 4B3 of different diameters, and furnished at its center with a cup leather B2. These difi yabove* the upper diaphragm VB3 communi-Y cates withy the atmosphere by means of the passagefl Lastlythe air from the brake reservoir reaches the orifice g3 situated vertically in the seat ofthe slide valve, by means of the openings g and g2. 'v

Figs 6, 7, 8 and 9 show the various positions of the slide valve, and corllO The air from the brake reservoir can enter the brake cylinder only by passing at the desired momentthrough the lateral passage a in the slide valve; thus this air has no influence upon the working of the distributer.

The opening b3 in the slide valve seat communicates with the atmosphere by way of the circular channel and the opening o5 (Fig. 2). i n The action of the distributer is as follows: "When the train is in motion, the parts -of the distributer occupy the positions shown in Figs. 1 and 6. The compressed-air from the train-pipe enters the-space C below the piston B, by means of thechamber c3, andpassages g and g2 to the brake reservoiry which becomes' filledl with compressed air at normal pressure. Thus both the brake reservoir and the distributer reservoir are in direct communication with the train pipe, while the brake cylinder communicates with the exhaust by means of thecentral recess a2 in the slide valve, and t-he passages e2 and es (Figs. '1, 2 and 5); the brakeis thus kept released and the air reservoirs are supplied from the train pipe. A

To produce an application of the brake ina controllable manner the piston successively occupies three positions, (a) prepara@ tory position, (b) neutral or cut-out posi-` tion (c) braking position. These three periods succeed eachother as rapidlyras the two periods of the Westinghouse valve and correspond to the following functions: (a) when the fall of pressure made by the driver has reached a given point,`the balance'of the piston B is destroyed and it descends with the slidevalve to the position shown in Fig. 7. The brake and distributer resei voirs are then cut olf from the train pipe fand from one another, because'the lower part of the slide valve has closed the orifice 64 from the train'pipe while the lateral pas! sage a of the slide valve has left the channel b of the seat of the slide valve. Atthe same time the brake cylinder is in constant communication with the exhaust by means of the central passage a2 of the slide valve It will be seen later that this position corresponds to the gradual releaseof the brake.

(b) 1f the pressure in the trainpipe continues to fall the piston rod B descends farther until the slide valve reaches the posi- Y the compressed Vair `evident-ly equaly to f tion shown in Fig. 8. The two reservoirs belonging to the brake and to the distributer, remain cut ofi" from the train pipe and from each other, as in the preceding position, but the brake cylinder is then cutoff from the exhaust, for the whole width of the slide valve completely covers the oriiice'b2 which leads to thecylinder. This is the neutral or cut-olfposition which produces neither braking nor release. v

(c) Upon a fresh fall of pressure in the train-pipe,`the piston rod Bof the dis tributer descends again and this time as far asithe end of the stroke, that is to say untilv it is stopped by the edge of the lower cover.

`The slide valve is th'englin the position shown in Fig. 9.

Y The two reservoirs, brake and distributer, still remain cut olf from the train-.pipe and from each other, but vthe brake `cylinder is put into communication with the brake reservoir by means Vof the lateral opening a in the slide valve which registers with the mouth of the orifice 212 leading to the cylinder. `The compressed air from the brake reservoir then enters the'cylinder, actuates the piston and the brake gear and applies thebrake by pressure of the brake shoesV on the vehicle wheels. But at the same time admitted into the cylinder enters the space beneath the diaphragm B3 and produces an upward pressure which tends to raise the piston rod B. This will continue until the pressure is suflicient to raise the piston 'and slide-valve to the neutral position. Now the fall of ypressure in the train-pipe, under the action of the air in the distributer reservoir, results in a down ward pressure on the surface of the diaphragm B whilefthe air admitted to the space' E acts upwardly on the surface of the diaphragm B3 and the surface of the cupleather pist-on. T hese surface areas may be conveniently designated SV for diaphragm B; S2 for the cup leatherrpiston B2 and S3 forthe diaphragm B3. t-is then evident thatgthe braking will automatically stop only when the pressure of air admitted to the ycylinder is in the. same proportion to the reduction in pressure in the train-pipe, as the surface S is to (S3-S2). This relation is Ss-Sz v thus itvis'constant and accurately determined 1n advance by the sizes given to the dia-V phragms. The brake is then perfectly controllable, because to every fall of pressure vcreated in the train-pipe there corresponds an accurately determined pressure in the brake cylinder. Further the intensity of the braking will bel absolutely the same for all thevehieles of the train, because the effort isl rigorously proportional to the lpres-` sure retained in the train-pipe, and is ,absolutely independent of the stroke of the brake vl. e. of the amount of wear on the brake shoes, because the action of the distributer is produced by a small separate constant-pressure reservoir and in no way dependsr upon the air stored up in the .brake reservoir where the pressure varies from one brake to another according to the Varying capacity of the brake cylinder that is to say accord-V ing to the amount of wear on the brake slices.

To effect the gradual release of the brake, the driver forces a certain quantity of compressed air into the train-pipe. The distributer piston then leaves the neutral position and rises to the position of F ig. 7. In this position the slide valve places the cylinder in communication with the exhaust by way of the passage a2 inthe slide valve, all this time keeping the brake reservoir completely cut olf.VK The air in the cylinder thus escapes gradually, and the braking eifort diminishes. But at the saine time the upward pressure of the cylinder-air upon the surface `SS--S2 of the upper diaphragm diminishes also, until the pressure is no longer able to maintain the piston rod lB which descends and takes up the neutral shut-off position. Thus there will come a time, as in the case of braking (but in t-he inverse .ma-nner),

when the fall of pressure made in the cylinder will be as many times greater than the increase iii thetrain-pipe, as the surface S `is greater than Sii-S2.. The relation is then S sT-T2 that is to say the same as that which governs the brake application. 'A fresh admission of compressed air to the train-pipe, will produce a fresh release but always rigorously proportional to the pressure in the trainpipe, and so on up to complete release, thatv is to say, until 'the brake is completely free. At this moment the distributer-piston will be completely raised andthe slide valve resumes the running position.

ln point of View of construction the distributer embodies thefollowing features:

(l.) There is arranged on the stem of the piston extended beyond the basin C, a second cup leather Bt of the same diameter as B2 but turned in the opposite direction. additional piston balances the action of the air on the upper piston and thus makes the apparatus very sensitive and facilitates the application of braking pressure.

(2.) The piston carries at its center, a cup leather instead of a diaphragm which arrangement considerably simplifies the'construction of the distributer and allows of more easily fitting up the parts and replacing the leather without having to dismantle the whole of the apparatus. it thesame This time the cup leather is stronger and wears away less thana diaphragm.

(3.) The two di phragms are mounted on the malleable iron pistons fixe-d separately kon the central stem, eachV by a single nut.

This arrangement allows each piston to be separatelyraised inl order to examine or replace one or other of the diaphragms,i without disinounting the whole of the apparatus.

Claims:

l. A. compressedair brake comprising an upper chamber and a lower chamber, and a passage between the same, a piston rodeateiiding through said passage fro-in one chamber to the other, a Aflexible diaphragm secured to said pistoni-od at eacli end within lsaid chambers, anda cup-leathermounted ff i on said rod in said'passageway "and forin-V ing av piston', a distributing slide igalyel mounted on the piston Vrod for controlling y the operation of the braking mechanism, and means for subiectmg said piston to unequal pressure on opposite faces thereofto operate said valve in combination with av well opening vinto'the' base of -the lower chamber, and having an internal diameter v corresponding to thatof the passage between the upper andlow'erchambers, a downward extension of the piston rod entering said well, a cup leather on said extension Vforming a piston in said well for the purpose ole'-V scribed, the well having an aperture below the piston to admit atmospheric pressure t the lower face of the latter. l

2. AV compressed air brake comprising an upper chamber and a lower chamber, and a passage between the same, ak piston rod eX- tending through said passage from one chamber to the other, a flexible diaphragm secured to said piston rodv at each end within said chambers, and a cup-leather mounted on said rod in said passageway and.

forming a piston, a distributing slide Valve mounted on the piston rod for controlling the operation of the braking mechanism, and means for subjecting said piston to unequal pressure on opposite faces thereof to. operate said valve, together with an air inlet chainber,` a baffle arranged therein in front of the air inlet port, an air passage behind said baille leading to the distributing valve `and a drainage passage leading to the lower diaphragm chamber, substantially as described.

8. A compressed air brake comprising an upper chamber and a lower chamber, and a passage between they same, a, piston rod extending through said passage froin one chamber to the other, a flexible diaphragm secured to said piston rod at each end within said chambers, and a cup-leather mount-A ed on said rod in said passageway and forming a piston, a distributing slide valve mounted on the piston rod for controlling the operation of the braking mechanism and means for subjecting said piston to unequal pressure on opposite facesthereof to operate said valve, together with an air linlet chamber, a baille arranged therein in front ofl the air inlet port, an air passage behind said baffle leading to the distributingvalveV chamber to the other, a ileXible diaphragmv secured to said piston rod at each end within said chambers, anda cup-leather mounted on said rod in said passageway and formi inga piston, a wellopening in the base of e Copies'of this patent may be obtainedffor ve cent'sreaeh, by addressing the Washington, D. C.

the lowerchamber, a downward extension of the piston rod entering said well, a cup leather mounted on said extension and form` ing asupplemental piston in said well, said well being apertured in Vits lower portion to admit atmospheric pressure to the lower face of said piston, a distributing slide valve mounted on the piston rod for controlling the operation of the braking mechanism and means for subjecting said piston situated between the diaphragme to unequal pressure on the opposite sides thereof to operate said valve. v

5. ln a compressed air brake of the character described, a piston rod threaded at its opposite ends, a slide valve mounted thereon intermediate its ends and moving with said rod, a piston adj acent-'said valve on said rod, flexible diaphragms one above and one below said slide valve and piston, carriers for said diaphragmssleeved upon the rods, a second piston of like diameter below the lower diaphragm, and securing nuts'threaded on the opposite ends of said rod to hold the parts in rigid relative position thereon, substantially as described.

In testimon7 whereof I have signed my name to this specification, in the presence of two subscribing witnesses.

JOSEPH DE LIPKOWSKI. `Witnesses: Y Y v JACQUES LEJENNE,

LEON PEiLLnT.

Commissioner of Patents. 

